Evaporative cooling has been used for centuries in the Arabic peninsula and is still more energy efficient than, say, air conditioning. It is based on generating a cloud of mist that cools the air around it while it evaporates. “In traditional systems, however, a lot of energy and water are consumed by cooling outdoor spaces, even when these spaces are sparsely used,” says Carlo Ratti. “In our project, we focus misting on people, which is considerably more energy efficient.”

Personal Cloud belongs to a larger array of studies on location-based temperature control infrastructure, that explore how to make public spaces in cities like Dubai more livable and sustainable by synchronizing human presence with climate control. “Urban life in all its diversity unfolds before us when we are on foot. We trust that by improving the conditions for pedestrians in Dubai, it will be possible not only to increase pedestrian traffic, but also – and most importantly – to strengthen city life,” says Pietro Leoni from Carlo Ratti Associati. “Moreover, we think that our canopy can contribute to a more diverse and attractive urban environment.”

The Personal Cloud installation at the Museum of Future Government Services recognizes visitors via sensors that activate a bi-dimensional array of actuators. More specifically, ultrasonic sensors embedded in the suspended canopy structure detect passersby by interpreting the echoes from high frequency sound waves. Measuring the time interval between sending the signal and receiving the echo to determine the distance to the floor, visitors passing between the sensor and the floor produce an increase or decrease in this time interval, having either absorbed or reflected the sound waves respectively. Data from these sensors is fed to a central control system used to trigger hydro-valves and LED lights in proximity to the detected target. The effect is that of a responsive mist cloud activated by the visitor and enhanced by backlighting.

“We envision the city of the future to be a place designed for people, giving them a chance to actually shape their environment and to fully experience their everyday lives and interactions,” says project manager Emma Greer from Carlo Ratti Associati. “Projects like Personal Cloud could help to make such a vision a reality.”